Clutch



Dec. 12, 1950 v L. E. LA BRIE 2,534,034

CLUTCH Original Filed Feb. 20, 1941 4 Sheets-Sheet 1 INVENTOR rig-E. 1, 37 zfj zrzlg.

ATTORNEYS Dec. 12, 1950 L. E. LA BRIE 2,534,034

CLUTCH Original Filed Feb. 20, 1941 r 4 Sheets-Sheet 2 INVENTOR 1244 2314, 1:-

ATTORNEY Dec. 12, 1950 1.. E. LA BRIE 2,534,034

CLUTCH Original Filed Feb. 20, 1941 4 Sheets-Sheet 3 ATTORNEY5.

12, 1959 L. E. LA BRIE 2,534,034

CLUTCH Original Filed Feb. 20, 1941 4 Sheets-$119024 INVENTOR A i/2541 h I; 6,

ATTORNEY- Patented Dec. 12, 1950 2,534,034 CLUTCH Ludger E. La Brie, Detroit, Mich assignor to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Original application February 20, 1941, Serial No. 379,786. Divided and this application'Ap fil 26, 1945, Serial No. 590,452

'1 Claims. 1

This invention relates to clutches in general and in particular to clutches of the servo type, and is a division of my copending application Serial No. 379,786, filed February 20, 1941, now Patent No. 2,374,688.

The principal object of my invention is to provide a servo clutch which is more compact, easier to operate and smoother in operation than those of the prior art.

An additional object is to provide a clutch of this type which is readily adapted for manual or power operation.

A further object is to provide simple and effective means for initiating operation of the servo mechanism for control-ling engagement of the clutch.

A still further object is to provide novel and efficient power actuating mechanism for clutches of this general type.

A still further object is to provide an expanding spring type clutch wherein torque may be transmitted in either direction, thus making possible use of clutches of this type in installations where overrunning or free-wheeling of one shaft or structure relative to the other is not desired.

Further objects and advantages will become apparent from the following description of preferred embodiments of the invention, reference being made to the accompanying drawings in which:

Fig. l is a longitudinal elevational View, partly in section, of an embodiment of the clutch adapted for manual operation;

Fig. 2 is a View of the clutch expansion spring and actuating lug as viewed along the line 22 of Fig. 1;

Fig. 3 is a fragmentary view of the parts shown in Fig. 2 as seen when looking in the direction of the arrow 3;

Fig. 4 is a sectional view taken along line i---@ of Fig. 1;

Fig. 5 is a fragmentary sectional view along line 5-5 of Fig. 1;

Fig. 6 is a fragmentary view of the Fig. 1 clutch adapted for differential fluid pressure operation;

Figs. 7, 8 and 9 are similar views showing the clutch adapted for operation respectively by magnetic means, by a solenoid and by eiectrical eddy current means;

Fig. 10 is a fragmentary sectional view along the line Ifii 0 of Fig. 9;

Fig. 11 is a longitudinal elevational view, partly in section, of a further modification; and

Fig. 12 is a sectional view along line l2-l2 of Fig. 11.

Referring now to Figs. 1-5, inclusive, my improved clutch is illustrated in a typical environment forming a releasable driving connection between a driving shaft l6 and adriven shaft I I. The former is preferably adapted to be driven by a prime mover and the latter connected to a'loa'd, such as for example, the input shaft of a motor vehicle transmission. It is, however, obvious that my improved'clutch is not necessarily restricted in'use to the specific relationship shown.

Splined on the driving shaft ID at I2 is the clutch driving element l3, which for convenience of manufacture is made up of two parts M and I5 riveted together at It. A retaining nut l1 threadedly engages the hollowed-out end portion of the shaft l0 and IB and serves to retain the clutch element i3 against displacement. The driven shaft H is reduced in size at one end and is piloted in the hollow end of s'haft'lll, an anti-friction bearing [9 rotatably 'separating'th'e two; The driven element of the clutch comprises the structure 26, which for convenienceof manufacture is made up of the parts 2| and 22 riveted together at 23. The element 20 is splin'ed on the shaft I I at 24. The'p'ortion 22 thereof carries the clutch engaging element which consists of a coil'spring 25 staked at one end thereof 25 (Fig. 2)'to the driven portion 22 by pins 25 and 21. The spring 25 is formed of spring material of substantially rectangular cross-section and is wound such that it is adapted to normally closely engage the outer cylindrical surface 28 of the.

portion 22 of the driven element 20. The opposite end 25 (Fig. 2) of the spring is adapted for engagement by a lug 29 which is riveted at 30 to the clutch pilot member 3!. A pin 25 (Fig. 2) retains the spring 25 endwise on the portion 22 of the driven element and may". also serve as a stop for the lug 29 of the pilot'clut'cli member when'the spring is released. The pilot member 3 I is of dished annular construction and is journaled on'the driven shaft "1 I at 3 2. A piece of friction material 33 is secured to the inner cylindrical surface of themembr 3,! and the parts are designed to be'assem'bled in such relation that 'the'friction material 33; which has a conically shaped inner surface,' is adapted to telescope the rearwardly extending portion of the driving element It as illufstrated'in Fig. 1. The latter is formed with a conicalblutch surface 33 with which the friction material 33fiS adapted to engage.

The member 3| is urged by a coil spring 35 into such position that the friction material 33 engages the clutch surface 34 and under such circumstances, clockwise rotation of shaft I will cause corresponding rotation of pilot member 3|. This will, in turn, cause the lug 29 to exert pressure on the rear end 25 of spring 25 tending to unwind the spring. Unwinding of the spring 25 will be accompanied by increase in diameter thereof and the outer surface of the spring will engage the inner cylindrical surface 36 of the driving element portion [5 thereby establishing a torque transmitting connection between the elements I3 and 20.

The spring 35 reacts against one race of an anti-friction ball bearing 36, preferably of the sealed type, which is prevented from displacement along shaft II by snap ring 31.

It is of course apparent that, as so far described, the clutch will transmit torque in one direction only. This is necessarily true because, if the driving thrust is shifted from shaft iii to shaft l l (as would occur upon coasting of the vehicle in a motor vehicle installation) the spring 25 will tend to wind up under inherent tension, there no longer being thrust imposed thereon by lug 29, and thus will disengage from the surface 36.

In order to prevent overrumiing of the shaft I l relatively to the shaft it) and to provide two-way torque transmission through the clutch, a reverse type roller clutch device is operatively disposed between the elements it and 29. clutch device comprises a set of overrunning rollers 38 which are retained in spaced relation by a cage 36, a spring 3!) being provided for urging the cage toward driving position as is conventional in these types of clutch devices. The outer surface of the member 2! is provided with a set This roller of cams ii in the vicinity of the rollers and these cams are so shaped that the rollers will wedge between the highe portions of the cams and the inner cylindrical surface of the member i4 whenever the member 2! tends to rotate faster than the member E6.

The pilot member 3! may be disengaged from the driving member 53 by a release mechanism which includes an anti-friction release bearing 32. The inner race thereof is staked to the pilot member Si by snap rings 45 and the outer race of the bearing has a driven fit with the inner cylindrical surface of a release collar 46. The latter has a shoulder 49 adapted for engagement by the depending ends 52'' of arelease yoke 48 which is keyed at 59 to a shaft 5!. The shaft 5% is adapted to be operated by any suitably constructed manually actuated mechanism such as a pedal or a hand operated linkage.

The operation of the clutch will be readily understood from the above description, it being apparent that the spring will act to engage the friction shoe 33 with the conical surface 34 of the driving structure, whereupon the pilot memher 3! will rotate in the direction of the driving structure and the lug 29 will unwind the clutch spring 25 carried by the driven structure which will frictionally engage the surface 35 of the driving structure and thereby establish a driving connection between the two structures. Rotation of the shaft 5i in a counterclockwise direction will disengage thefriction shoe and conical surface thus permitting release of the said driving connection because the spring 25 will immediately contract due to its inherent tension in response to a release of pressure at the lug 29.

Tendency of the driven structure to overrun 4 the driving structure will also permit the spring 25 to contract and under these conditions the drive will be transmitted through the rollers 38 which will wedge between the members M and 2 i. By properly adjusting the clearance between the rollers 38 and the cams 4| with relation to the slight rotation required to fully engage the spring 25 with the member l5, it is possible to reduce the backlash upon torque reversal to an extremely small amount which is practically unnoticeablc. When the pilot member 3i is disengaged, the driving shaft 10 is free to overrun the driven shaft ll, but the driven shaft II is prevented at all times from overrunning the driving shaft 50.

With the parts illustrated, it is possible to transmit approximately fifty times more torque through the friction connection established by the spring 25 than through the friction connection between the shoe 33 and the surface 3d. Any other mechanical advantage derived may of course be obtained by varying the sizes and adjustment of the parts.

My improved clutch is particularly Well adapted for power control and I have illustrated several diiferent applications thereof.

Fig. 6 illustrates the clutch of Fig. 1 adapted for fluid pressure control. The pilot member 3% in this form of the invention is formed with an overhanging annular portion 52 which forms a fluid pressure cylinder adapted for reciprocation along the shaft l i against the spring 35*; a bearing 36 accommodating relative rotation between the pilot member and the spring. A stationary piston 53 surrounds the shaft 5 E and has a chamber 54 which communicates with a source of pressure fluid through a pipe 55. The chamber 54 is connected by a passage 55 with the chamber 5! of the cylinder 52. A snap ring 58 prevents rearward axial movement of the piston 53 and suitable rings 59, 6t and (ii are provided to insure a fluid-tight assembly. By providing a suitable valve for controlling admission of pressure fluid to chamber 54 the engagement of the pilot member 3| with the clutch driving element l3 may be controlled.

Fig. '7 illustrates the Fig. 1 clutch adapted for magnetic control. In this modification the portion 15' of the clutch driving element 53 is formed with a rear annular portion 62 which carries a field coil 63, the latter'being connected by a wire 64 with a collector ring 65. The ring 65 is carried by an insulating ring 63 carried by the member I5 A carbon brush $6, carried by an insulating plug 61, is connected by means of a wire 69 with a source of electrical potential, the return being effected through the metal of the assembly, which is intended to be grounded in accordance with conventional motor vehicle practice.

The brush 66 is mounted on a. stationary part of the assembly 10 through the intermediary of a threaded plug H which is provided with a bore for receiving the insulating fitting 61' and a spring 72 which is adapted to urge the brush 66 into contact with the collector ring 65. The clearance between members [5 and 31 is slight (in the order of eight to ten thousandths) and a friction ring 13 of asbestos fibre or other suitable clutch facing material is carried by the annular portion 62 as shown.

Upon energization of the field coil 63, the pilot member 3| will be attracted by the magnetic flux flowing around the magnetic circuit surrounding the coil and will move axially against the force of the spring 35 into contact with the member I5 A snap ring 14 limits the movement at"; i i ini i foic 9 r the des'ired clearah In t e form of the invention illustrated in Fig.1 8; an electrical solenoid, generally desigfiated at 15 controls the action of the pilot menig b'er 3l 9 The solenoid includes a field 'coil H3 @r ..b n1ir fiel meme ll whi hzis mo t d .o a sta a rt 18 .ifth ga s rab k h iil t iii hi are rve dl exte g S sv i portion I9 which is reducedtoreceive' an annular on. 9 79- 9 he. a te bein held a i s dis; placement on the aforesaid reduced portion by fiQ Ii I- The c oil 16 is grour'iderltjo themetal struc ture atj one end and the other end is adapted we. c miied dh a i e 82 w h a Source off electrical energy, a suitable contact structure 83 being provided; Inasmuchas the coil 16 is stationary, no brushor slip ring' is necssa'ry.

The pilot M is normally urged axially against ther'i'ng 84 by the spring 35, andupon enerf gizatio'n of the solenoid field coil" '56 moves axially toward the leftof Fig. 8 to engage the friction shoe 33 of the pilot clutch.

series a In this modification, the pilot 3 I andthe ring 18" which separates the field structure from the part 18 are preferably made of stainless" steel which of extremely high reluctance, thereby confining the flux path to the non of the sore:

noid.

Figs. 9 and illustrate the Fig. 1 clutch adapted for eddy 'current control. In this form of the device, the stationary part of the assembly 84 carries an annular iron field structure 85.

The latter is U -shaped in cross sectionand car ries a field coil 86 adapted for energizatiori through a wire 8'! connected to' one end thereof, the other end of the coil being grounded. A stainless steel separator ring 88' is interposed be tween the field structure 85 and the portion 84" and for best results, the driving member l5? and the pilot Si are also preferably made of non-magnetic material.

An iron ring 89 is riveted at 90 to theme'in' ber I 5 and constitutes the driving element oi the eddy-current pilot clutch structure. The ring 8915 provided with a plurality of circumferentially equally spaced teeth 9! around its inner surface. The teeth 9! are adapted to align radially with a similar set of teeth 92 formed on the outer periphery of an iron ring 93 car ried by the pilot member Si as illustrated. The pilot member has an integral lug 29 for actu'ating the spring 25 and is fixed against axial displacement on the driven shaft H by washer 94 and snap ring 95.

Energization of field coil 86 will cause magnetic flux to flow through the field structure 85 and across the air gap between the bifurcated portions thereof. The reluctance of the air gap will of course be lowered by the presence of the iron of the members 89 and 93, and because of the juxtapositioned teeth on these members there will be alternate regions of high and low flux density, the flux being high in the regions of the teeth and low in the regions between the teeth.

7 Upon rotation of the driving member 89 therefore, a point on the latter moves alternately through regions of high and low flux density, thus the flux flowing through said point varies in magnitude and eddy currents are induced in the members 89 and 93. These eddy currents flowina direction perpendicular to the path of the flux and range in voltage in accordance with H the speed of the driving member 89'. They in b cti ccr s e an; "Ha sel; in e it i' so 23. 'ci d' ha its ma n w efieot'tendsto oppose th magnetic change meal q' i The seed; of then 1:15;" sowing thr'ciugh the teeth ajg and 92 then will be to etsas'egrlesve rate-uni Between nimtere 39 arm 93' an as is rotatedat in speed of the" driving s'ha'lft' mf, the member 93: together with the" pilot" 3]? will be rotatdi so 1011?;- as there is s'uppage petween m m ers 89 and 93' there will eXist an eddy curre produced torque teasing to ace-a rate the" member 93 to sp'ed of member 89'. when the two members" are rota-ting in synchronism; a given-- point either of members 89 and 93 will be subjected to sex or constant'ma' nitude and no eddy currents will be induced. Under this condition the holding force tending to keep the members 89 and 93 in synchronisni will be entirely magnetic. It is, however, apparent that any tendency for the member 93 to slip will be instantly opposed by the eddy current 'produced torque;

.In practice it will befound that. thespring 25 grips the member I5 very quickly after coil 86 isenergize'd and the magnetic effect of .the flux flowing through the teeth 9l, 92is sufiicient to provide the force necessary to keep the spring expanded.

. It is believed to beapp'arent that the clutches illustrated in ,Figs. 6 to 10,; inclusive, operate similarly to the clutch of Fig. 1, it being intended in all of the various forms of the,inv,ention to provide a ratio of approximately fifty to one between the torque transmitted by the pilot clutch structure and that transmitted through the clutch as awhole. I a I Any of the various modifications are adapted for automatic as well as manual operation as Lhe pare 0 t s l d. in thee -4. and 2 i u rate .a acid e rm; o the enticn. whe t ve s i que is r mitted throughnthe pilot clutch structure, In this. form. 9 h n en o theco ern nine rollers 38 areof smallersize than those used in the above described i orm's and are disposed between the drivn shaft u on which the ains a formed nd ihe pr iefi r i e ,lus hevle er h i een' nt ra r e j t SB'L adaptedtQ be engaged by the rollers 38 The roll'er cage 39 has a lug which engages a groove in the shaft II at 96 for maintainin the rollers against aXial displacement. In oper am. fi r' iing hi e ee z d..bae e. as whichis dr ven through the pilot s I (hiring;010151; wise rotation of: meshe {0) When shat it tends to overrun shaft l l, the lug 29? is rotated through the friction shoe' 3'3g aiid .whn shaft run shaft! -the uggza' a u pilot J. -t' wu' e i he reverse torque tted from shaft ll to shah thr gh w i' i Show? t s 6f i r I 1 o sharia ,5

ease member 4%" a of shaft l l against sprin 35, the friction shoe 33 is disengaged from the conical surface of the driving structure, the lug 29 is disengaged from driving engagement with the spring 25, and the rollers 38 cannot establish a drive between the shafts. Thus the driving connection between shaft l6 and II is completely broken. In the previously described forms, the overrunm'ng rollers are disposed directly between driving and driven members of the clutch, therefore the normally driven shaft H can never overrun the normally driving shaft It. even when the energizing lug is in non-energizing condition.

It is of course obvious that the construction of the Fig. 11 clutch may be readily applied to the power actuated clutches of Figs. 6-9, inclusive, to provide two-way torque transmission and to permit complete release of drive between the two shafts; consequently a detailed description is believed unnecessary.

I claim:

1. In a servo clutch mechanism having a driving member and a driven member; means for establishing drive between said members positively drivingly connected to said driven member and a control structure for actuating said drive establishing means comprising differential pressure motor means including a cylinder element journalled on the driven member and a piston element, one of said cylinder and piston elements being axially movable relative to each other, a clutch structure operably connected between said driving member and the movable element of said motor means for imparting drive therebetween, means operatively associated with and having relative rotation with respect to said drive establishing means and carried by said movable element of said motor means for actuating said drive establishing means when said movable element is in drive and means for controlling differential fluid operation of said motor means.

2. In a servo clutch mechanism having a driving member, and a driven member; means for establishing drive between said members positively drivingly connected to said driven member and a control structure for actuating said drive establishing means comprising a rotatable element operatively associated with said drive establishin means and having relative rotation with respect thereto, engageable friction clutch elements carried respectively by said driving member and said rotatable element, differential pressure means for effecting engagement and disengagement of said clutch elements including a piston and a cylinder coaxial with said driven member and interengaged with each other, one of said piston and cylinder carrying said rotatable element and its friction clutch element being axially movable and journalled on said driven member, spring means for positively releasing said clutch elements; and means includin a connection to one of said piston and cylinder for controlling flow of differential pressure fluid to and from said cylinder.

3. In a servo clutch mechanism having a driving member and a driven member; means for establishing drive between said members positively drivingly connected to said driven member and a control structure for actuating said drive establishing means comprising a rotatable element journalled on said driven member, said element being operatively associated with said drive establishing means and having relative rotation with respect thereto, releasable friction clutch means between said driving member and said rotatable element, differential fluid pressure operated means for effecting engagement and disengagement of said clutch means including a stationary piston journalled on said driven member, a cylinder carried by said rotatable element and surrounding aid piston, a spring for positively ur ing said clutch means to disengaged position and means for introducing pressure fluid into said cylinder for moving the same against the force of said spring.

4. In a servo clutch mechanism having a driving member and a driven member; means for establishing drive between said members positively drivingly connected to said driven member, and a control structure for actuating said drive establishing means comprising a rotatable element journalled on said driven member, said element being operatively associated with said drive establishing means and having relative rotation with respect thereto, releasable friction clutch'means between said drivin member and said rotatable element, a differential pressure motor including a piston carried by said driven member, a cylinder carried by said driven member and interengaged with said piston, and means for controlling flow of differential pressure to and from said cylinder, one of said cylinder and piston being integral with said rotatable element, spring means for positively releasing said clutch means and an anti-friction thrust bearing between said spring means and rotatable element.

5. In a servo clutch mechanism having a driving member and a driven member; spring means expansible for establishing drive between said members, said spring means being positively drivingly connected with said driven member; a rotatable element journalled on said driven member, said element being engageable with said spring means for expanding the same and having relative rotation with respect thereto; a clutch member carried by said driving member; a second clutch member carried by said rotatable element and engageable with said first clutch member to establish drive between said driving member and said element; a differential pressure operated motor having a movable member integral with said rotatable element, operable for engaging said clutch members and means for positively disengaging said clutch members upon operatin said motor to permit said disengagement.

6. In a servo clutch mechanism having a driving member and a driven member; a spring means expansible for establishing drive between said members, one end or" said spring means being rigidly drivingly connected to said driven member, the other end being free; a rotatable member journalled on said driven member, said member being engageable with the free end of said spring means for actuating said spring means to expand the same and having relative rotation with respect thereto; a friction clutch element carried by said driving member; a second friction clutch element carried by said rotatable member and engageable with said first friction clutch element to establish drive between said driving member and said rotatable spring engaging member; a diiferential pressure operated motor having a movable cylinder integral with said rotatable element, operable for engaging said clutch elements and means for positively disengaging said clutch elements upon venting said motor.

7. In a servo clutch mechanism having a driving member and a driven member; a spring operable for establishing drive between said members, one end of said spring being rigidly drivingly connected to said driven member and the other end being free; an axially movable rotatable member jounalled on said driven member, said rotatable member being engageable' with the free end of said spring and having relative rotation with respect thereto and said rotatable member having a hub portion providing a fluid motor cylinder; means carried by said rotatable member for actuating said spring to establish said drive; a friction clutch element carried by said driving member; a second friction clutch element carried by said rotatable member and engageable with said first mentioned friction element to establish drive between said driving member and said rotatable spring engaging member; a piston member carried by said jdriven member and held from axial movement relative to said rotatable member; and resilient means for biasing said rotatable member to disengaged position relative to said driving member.

LUDGER E. LA BRIE.

10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 875,757 Watson Jan. 7, 1908 949,559 Wilson Feb. 15. 1910 1,007,335 Carroll Oct. 31, 1911 1,254,951 Ward Jan. 29, 1918 1,364,392 Macho Jan. 4, 1921 1,416,283 Gmeinder May 16, 1922 1,844,935 Hinger Feb. 16, 1932 1,935,684 Wemp Nov. 21, 1933 1,939,974 Gifiin Dec. 19, 1933 2,214,391 Weydell Sept. 10, 1940 2,226,309 Gleasman Dec. 24, 1940 2,272,495 Winger et al. Feb. 10, 1942 2,282,143 Carter May 5, 1942 2,374,688 La Brie May 1, 1945 FOREIGN PATENTS Number Country Date 340,846 Germany Sept. 23, 1921 348,434 Germany Jan. 4, 1921 629,226 Germany Apr. 24, 1936 

